Is your phosphate a Na-K phosphate? If it is, then you're probably getting a K salt of SDS which is considerably less soluble than Na or Li salts.
Artem -----Original Message----- From: CCP4 bulletin board [mailto:ccp...@jiscmail.ac.uk] On Behalf Of Subscribe Ccp4Bb Kn L Sent: Wednesday, December 17, 2008 9:26 PM To: CCP4BB@JISCMAIL.AC.UK Subject: [ccp4bb] LDAO & SDS-PAGE Hello everyone... I have a protein solubilised in 1% LDAO, 50 mM Phosphate pH 7.5, 150 mM NaCl. When I mix it with laemmli buffer and heat at 95C, 3 mins for SDS-PAGE, it aggregates (as in when you mix GuHCl with SDS) and can't be loaded onto the gel. Does anyone know why it happens? Thanks a lot!!! Kien